Recent imaging devices such as video cameras and digital still cameras use complementary metal oxide semiconductor (CMOS) image sensors as image sensors to capture images.
This kind of image sensor reads an electric charge generated by a photodiode provided in each pixel to obtain a pixel signal from each pixel (refer to Non-Patent Document 1, for example). A technology disclosed in Non-Patent Document 1 employs a common-source amplifier configuration and uses gate-drain parasitic capacitance to read a pixel with high conversion efficiency.